Hydraulic manifold design is a complex, iterative, labor intensive and time-consuming process. While designing a manifold, a designer consciously works to minimize the size of the manifold and total number of cross-drills, while adhering to many complex and conflicting design constraints.
A hydraulic manifold is a solid block of aluminum or steel which has various hydraulic valves mounted on it (see FIG. 1). Drilled holes, called Cavities, are machined into the manifold block to house any valves and create required flow passages. Manifolds typically have a rectangular cross-section. The six faces of the cuboid manifold are named as shown in FIG. 2.
Cavities are precision-machined holes in the manifold. Geometrically, the formulation of each cavity is composed of a number of steps, which are machined with drill tools of varying diameters or by a form tool (see FIG. 3). Every cavity has zero or more ports (also known as working areas). FIG. 4 shows a cavity with 3 working ports. Ports are locations on the cavity, and are meant to accommodate connections with other cavities. All regions of a cavity surface, apart from ports, are called dead areas. Connections can only be made at ports on a cavity.
Cavities, for the purpose of defining this invention, are classified into two types: primary cavities and cross-drills.
Primary cavities are those cavities that accommodate valves and components defined in the input hydraulic circuit and which necessarily have to appear in the corresponding manifold. Each primary cavity has one or more than one ports.
Cross-drills, are single port cavities (containing only bottom ports) that are used only for making internal connections between primary cavities. While a designer must place on the manifold each and every primary cavity as required by the circuit, the number, shape, or the placement of cross-drills is entirely upon the manifold designer's choice.
The existing technique of manifold design, i.e., the current state-of-the-art, requires an engineer/designer to place cavities on the manifold surface and individually and sequentially connect them with each other inside the manifold, while meeting various design requirements such as flow considerations, internal wall-thickness, external clearance between components, etc. A good design is one that not only satisfies all such constraints, but also keeps manufacturing costs, e.g., volume of manifold, number of cross-drills used for connections, and the total drill length, etc., to a minimum. Manual manifold design is labor-intensive. Using CAD software tools available in the market, a skilled designer typically takes anywhere from eight to one hundred man-hours to design a manifold.
It would be desirable to provide a method to automate design of the hydraulic manifold, given a circuit and system constraints it would also be desirable to provide such a method which will not only make the design process almost instantaneous, but will also achieve significant improvements in the quality of the manifold design.